The Numbers behind Safe and Unsafe Carbon Monoxide Levels

While excess levels of carbon monoxide can be detrimental to your health, CO is still a gas that is ever-present in the air of your home. In order to understand when your health is at risk and when it’s not, it’s important for St. Louis area homeowners to know the numbers behind safe and unsafe carbon monoxide levels.

How carbon monoxide levels are measured

Carbon monoxide is measured in a unit called parts per million (ppm). It is a measurement of the amount of CO that is present in a million particles of air.

Health effects at different carbon monoxide levels

If the level of carbon monoxide in your home is at a normal level, most people won’t experience any symptoms of CO poisoning. The EPA’s limit for air to be considered normal is a CO level of 9 ppm over an 8 hour period and 35 ppm over a 1 hour period.

When the CO content begins to get higher than that due to something like a CO leak from a cracked heat exchanger, it starts to have health effects on the people in your home. At a ppm of 35-400 over a 1-3 hour period, many people will experience headaches and loss of judgment. At around 800ppm, dizziness, nausea and convulsions can set in within 45 minutes. Anything higher than that is considered extremely dangerous and can even lead to death.

The alarms in CO detectors are designed to go off at specific ppm levels over specific periods of time. If the ppm is at 100, for example, the alarm won’t go off unless it remains at that level for around 10-20 minutes. If the ppm goes up to 400, the alarm will go off within a matter of minutes. This is done in order to prevent false alarms from short term exposures to higher levels of carbon monoxide.

If you have any questions about carbon monoxide levels, or would like your home’s air quality checked by a certified professional, contact Jerry Kelly, your St. Louis area heating and cooling company.